The long term objective of this study is to develop a microcarrier substrate for growing fastidious anchorage dependent cells which is superior to current microcarrier products. Microcarrier systems show great potential for the large scale growth of cells and the production of their metabolic products. The aim of Phase I is to produce microcarriers of near ideal size and density from several inorganic materials and then to evaluate their ability to support the growth of human diploid fibroblasts in small scale stationary and suspension cultures. Inorganic materials have the potential to be cost effective in industrial systems because of their expected durability and thus their potential for reuse. Current polymer based microcarriers have little potential for or are intrinsically not reusable. The materials selected for this stucy Lsi, SiO2 one type of (glass) have been shown to support growth in a conventional monolayer culture. In addition a large amount of recent data from the field of cell biology shows the tremendous influence the substrate has on the biological behavior of cells. Thus the inorganic materials chosen masy also have the potential for supporting improved cell growth and/or more favorable metabolic activity. Our preliminary studies have shown that a variety of cells grown on one type of glass microcarrier were indeed biologically different from cells grown on dextran based microcarriers. The microcarriers will be produced by physical vapor deposition, specifically sputtering. Using this technique the oxygen content can be controlled from Si (no oxygen) to SiO2; thus altering the surface charge state of the microcarrier. The simplicity and economy of the fabrication processes will also be considered. The microcarriers will be 100-150Mum in diameter with a density of approximately 1.04 g/cc. These parameters maximize the surface area while still supporting cell growth and are nearly neutrally bouyant in our culture media. However, both the size and density can readily be varied in our manufacturing process. Biological activity will be evaluated by conventional cell cultivation protocols and quantitation techniques. Growth of the MRC-5 strain of human diploid fibroblasts on the test materials will be compared to monolayer cultures and commercially available DEAE dextran type microcarriers in stationary and suspension cultures.